Catheters find their use in many different medical applications, such as urinary catheters for bladder drainage. Each catheter is normally pre-packed in a receptacle by the manufacturer, in order to maintain the catheter in a clean and preferably sterile condition.
A urinary catheter in general need to have a lubricant applied to the outer surface thereof to facilitate insertion into the urethra. Especially, for lubrication purposes, a hydrophilic urinary catheter may have a hydrophilic outer surface coating or layer which should be wetted by a fluid such as water for a certain time period prior to insertion of the catheter into the urethra of a patient. In order to facilitate the use and to improve cleanliness of the catheter, the assemblies have in recent years developed to comprise a rupturable wetting fluid pouch or container as well. Such assemblies are disclosed in e.g. WO 97/26937, WO 01/43807 and WO 98/11932.
The purpose of a urinary catheter is to drain out the bladder into which it is inserted, and to this end, the catheter tube is normally at the outside end connected to a collection container or collection bag. However, the possibility exists that, should e.g. the collection container be crushed or raised above the level of the bladder being drained, the drained urine may flow in reverse, and reenter the cavity from which it was drained. This is not only uncomfortable and possibly painful for the patient, but may also cause introduction of bacteria and the like into the bladder. A related problem is that there is a significant risk for spillage through the catheter after the catheterization, when the catheter has been removed from the bladder.
To this end, different types of catheters with check valves arrangement integrated therein have been proposed in the art. For example, such catheters are disclosed in US 2004/0172009, U.S. Pat. Nos. 4,227,533 and 6,682,503. In all these catheters, the check valve arrangement is integrated in the catheter, thereby providing an anti-reflux valve some way along the internal lumen of the catheter. Even though these known catheter may be sufficient for alleviating the above-discussed reflux problems, these known devices are all affected with certain drawbacks. For example, a common problem with all these known devices is that they are relatively complicated and expensive to produce. Consequently, these known solutions will normally not be considered for urinary catheters, and especially not for disposable single-use intermittent catheters. Further, the solutions proposed in the prior art will normally restrict the flow throughput of the catheters. i.e. increasing the flow resistance, thereby making the catheters less effective for their intended use. Still further, the previously known solutions for providing anti-reflux valves in catheters are unsuitable for use in catheters provided with a surface coating, such as a hydrophilic surface coating, since it is difficult to avoid coating building up in the vicinity of the anti-reflux valve during manufacturing, which may affect the valve in a negative fashion.
In addition, urine collection bags with integrated check-valves have been proposed in the past, e.g. in EP 0 185 809. However, such known collection bags are affected with a number of drawbacks. For example, these solutions are not suitable for urinary catheter assemblies where the urine collection bag is integrated in the receptacle accommodating the catheter before use, since the check-valve would then prevent easy and effective activation of the assembly, and would also hinder an effective wetting of a hydrophilic urinary catheter, especially for assemblies comprising a rupturable wetting fluid pouch or container.
Accordingly, there is still a need for an improved catheter assembly which alleviates the above-discussed problems of the prior art.